I would like to point out that evil doesnt mean sadistic, or masochistic, or any other illness..
I like to point out to my players sometimes, yeah you can take him, but do you really fancy shiny new stab-wound? Even though the players cant feel the pain, its important to the game that the character act like they do..
Also that Neutral Evil isnt reserved for sociopaths, the neutral evil Rogue can also see the value in friends, and is even capable of trust and love, he may reserve this for only the closest, few are truly alone.. Joker (Chaotic Evil) Has Harlequinn.. Batman (Neutral Evil) has Robin, so on and so forth..
Player dynamics ar best when they argue and fight a bit, but it never gets lethal.. So as Gary Suggested i used the Evil Boss, a rich aristocrat representing hell and their interest.. Though the anti-paladin in the group still channels negative energy without regard for the team-mates, even doing it if he needs to get rid of bedbugs

The Barbarian charging at a merchant overpricing his goods.. But in the end of the day when the Anti-paldin was thrown at the Colossal Wyvern, stabbing it to death 400 ft in the air, as he plummeted to his death the other players rushed to his aid, filling him with all the healing potions they could muster, just for the off chance it would work..
I agree with Gary that some tasteless evil acts should be ignored, or avoided, though its important to know this border, as the gore and maybe more mature subjects is what the group is seeking.. It could be as simple a describing the barbarians attack "He swings his axe, imbedding it into his foot, Ragnar proceeds to grab the puny human by the neck, gouging his eyes with the other".. With the introduction of Eremites, and kytons, Dnd, pathfinder and fantasy gaming really began opening up to some really gory stuff..
Evil is too active

it can be hard to keep up with players, so i keep the storyline loose, and keep a buttload of encounters ready..
And i would like to say thanks to everyone for giving me a helping hand, we really got a fun campaign going!